There are a variety of circumstances in which it may be desirable to close or seal the open end of a hydraulic, pneumatic or other fitting. For example, when hydraulic equipment such as a construction vehicle or the like, is being serviced, oil-filled hydraulic lines, pipes and fittings are often disassembled during service and maintenance procedures. Much of the oil, or other working fluid, can be drained from many of these components without undue difficulty but a residue will often remain within the lines, pipes or fittings. This residual oil is prone to drip or drain from open fitting ends during service procedures, and may contaminate equipment surfaces, floors and other surfaces in the vicinity of the work area creating dirty, slippery and perhaps dangerous conditions. It is accordingly desirable to provide an end cap to close such open ends that can be easily manipulated in a service bay, a workshop or in the field and can be assembled with an open ended fitting to close or seal it either by manual manipulation or by the use of simple tools. The presence of an annular flange around the end of some fittings may complicate the end closure problem.
To attempt to solve this problem it is known to provide a plastic cap to cover the fitting end. One example of such a plastic cap is a simple, lightweight, dish-shaped resilient cap which is a close fit over a flanged pipe end and has a modest retaining lip engageable under the flange. Such plastic caps appear to be intended to keep out dirt and may retain some oil within the pipe they may not be satisfactory for some purposes because they are readily removed and cannot hold pressure. These shortcomings can be problematic in some cases, for example when it is desired to pressurize a flanged hydraulic fitting for test purposes or other reasons.
The patent literature contains proposals for end caps for hydraulic fittings. For example, U.S. Pat. No. 7,134,454 to Montminy discloses an end cap for blocking a pipe which employs a latch movable between latched and unlatched positions to engage a rim around the end of the pipe. Also U.S. Pat. Nos. 4,205,707; 4,887,646; 4,982,763; 6,135,156; disclose various caps, plugs, closures or fittings for pipes, tubing and the like.
Nevertheless, there is a need for an end cap that can be used to cap a flanged hydraulic fitting and which can be employed in a hydraulic equipment service facility and for other purposes.
The foregoing description of background art may include insights, discoveries, understandings or disclosures, or associations together of disclosures, that were not known to the relevant art prior to the present invention but which were provided by the invention. Some such contributions of the invention may have been specifically pointed out herein, whereas other such contributions of the invention will be apparent from their context. Merely because a document may have been cited here, no admission is made that the field of the document, which may be quite different from that of the invention, is analogous to the field or fields of the present invention.